Harey

No longer needed, please close thanks.

Received in excellent condition and very prompt!! Thanks heaps. Please close thread.

Just put some bilsteins on my 34GT-T with some king springs and its fantastic for both comfort and handling. Both improved after taking out high spring rate coilovers. Its faster and more comfortable in every situation.

Thats exactly whats happening in this scenario but just for a different reason. The wastegate is unable to open completely due to an issue with the dump pipe. This can cause the boost to creep as the wastegate opening at say 80% is not able to flow enough air to maintain the same boost level.

Bugger I bought one of these a few months ago and was hoping to get it fitted when I hiflow the turbo. Might not bother with it. What is the cost for someone to make up a custom 3" dump pipe including fitting etc?

+1 for nistune!! cost me $800 for a type 4 board installed with a tune. very happy and its now there for when I hiflow the turbo. plus it is all internal to the ecu so no hassle from the cops!

They could be talking about other cars with crapper airboxes. I know my old commodore loved the pod filter over the airbox, although i did have it mounted under the guard for heat shielding as well. It was also a 4" pipe with 4" super long pod hehe. The commy airboxes are crap though.

Thanks, just wondering what is the difference between an OP6 and a 0.63 exhaust housing?

yeah you need a bigger front pipe then as well. from what i have read on this forum the 34 gtr dump pipes are a great upgrade too. you have chosen some very hardcore turbos and it seems strange to limit them so much. theres a thread on here with an article from a garrett engineer about how important it is to have a big enough exhaust for your turbos. also that exhaust after the turbo cannot be too big performance wise, although there are obviously size restrictions and minimal gains once you go above a certain size. there is a lot of info here, first thing I would do is read through the rb26 dyno thread and see what exhaust people are running for each power level. there is a lot of info there. that will also tell you whether you need larger afms, whether an EBC is required etc etc.

SKYPER is just saying the ones he has tested have been closer to 12psi. Either way do they work on a stock turbo ie hold boost constant to redline?

haha did i not post that right at the top. basically the airbox is fine till you start replacing the turbo etc. even then its not always a big difference. but if you want to hear the turbo then they are fantastic

Moreso to Tao but keen to hear your response too. With the PU hiflow turbos do you get a choice between 0.63 and 0.82? What is the difference between an OP6 and a 0.63 exhaust housing?

Quick look through the RB26 dyno thread showed me few guys running stock GTR afms at 280rwkw, but everyone I saw over 300rwkw had upgraded theirs. I think for your goal power you should definitely upgrade them. Is there any reason why you are sticking with the 3" exhaust? Ignore the comment from your tuner about a proper EBC, spend the money on a bigger exhaust and some upgraded afms. $28 turbotech boost valve is all you need.

I am saying even after a tune the stock turbo with stock actuator struggles to hold boost to redline. Mine dies off from 10psi to a bit less than 9psi. My question is does an R32 actuator make a constant 12psi to redline on a stock rb25 turbo?

Thanks all! Very helpful. I though all PU options were 0.82 housings? Isnt the OP6 housing already a 0.63 housing?

Exactly right. I just went through this whole process of taking out stiff coilovers. My process was: stock suspension both springs and shocks are too high. Stock shocks and lowered springs will wear out the shocks very quickly, plus the handling will be poor in the meantime as the shocks cant control the lowered springs properly I ended up doing the following: Bilstein shocks with lowered king springs End result great handling and comfort. You literally dont feel smaller bumps and the larger bumps feel like small bumps. The car is also faster on any imperfect road and i honestly cant tell the difference in handling even on a smooth road. The big thing is that you know its going to last. Would be a shame to go to all this effort for poor handling and then have to swap the shocks again. I had to obtain some strut tops as the coilovers replace them, thats on an R34 GTT so it might be different on the GTR.

Hi Tao, I have a question regarding the R34 OP6 hiflow dyno sheet on your website: http://www.digi-hardware.com/images/dynosh...g3OP6hiflow.jpg I am wondering why the boost drops down from 17 to 14psi as rpm increases? Is a large can actuator required? Have you managed to hold 17psi to redline on any internally wastegated cars with the hiflow OP6 turbo?

I wonder then is 10psi from a stock 5psi wastegate too much for it to hold 10psi to redline? I have never seen a stock turbo hold a constant boost to redline (above 10psi) on a dyno sheet. What are peoples dynos like that use the R32 10psi actuator?

A boost controller can only do so much. It is limited by the wastegate actuator. Geeze yeah asking a 5psi actuator to run at 15psi is a bit much to ask really.

What a setup! The engine bay is a work of art! That dyno curve is so fat, the mid range is so strong. The twin scroll setup is obviously working wonders. A 3076 would be very interesting...

Pretty much all of the standard turbo dyno graphs i have seen drop off boost towards the top end. An actuator that is closer to the boost pressure you want to run can only be a good thing. There are some other threads on cars with bigger turbos that experience worse boost tapering off, their solution was a large can higher boost actuator. This solved the issue. I strongly disagree that the factory BOV leaks above 10psi. There are many threads about how good the factory BOV is and there is no point in replacing unless its a really hardcore setup. Many 300rwkw cars running factory BOVs. Higher boost actuator ftw

I have the apexi power intake pod filter. It seems to get good ratings. Although, my car came with the pod already on there. If you are putting a pod on for noise reasons, louder turbo spool and so you can hear the stock blow off then fine. But if you are doing it purely for power dont worry about it.

Ok I had the suspension changed over last week. FineLine and Proximity were correct, you only need the stock top hats. Also, R33 stock top hats are the same as R34 ones. Thread is resolved.

I find that very hard to believe, something must be wrong with the commo. I have a 190rwkw R34 and have raced my old mans tuned ls1 (~225rwkw). With a similar launch mine will get a nose in front and keep gradually pulling away. It does beat it but does not smash it. I would think a 290rwkw cammed ls1 would beat me no probs. I have driven a cammed ls1 and it definitely feels faster than my car. although i have never put them side by side. Although I have seen a 225rwkw 1350kg commo sit side by side with a ~1700kg 300rwkw cammed ls1 car.

Hahaha I didnt mean go out and buy it this second, just saying if you are going to buy an ecu that is what I have and would recommend. Yup type 4. Dr Drift charged me $800 for type 4 board fitted with full tune. So somewhere around 300 for the board installed.